Production of alkaline earth metal cyanamides



-Patent ecl July 25, 1933 UNITED srATas- PAT N I? Hans ACKER, 01f LUDWIGSHAFEN-oN THE-RHiNE,' GERMANY, ASSIGNOR ro I; G. FARBENINDUSTRIELAKTIENGESELLSCI-IAFT, OF FRANKFORT-ON-THE-MAIN, GER? MANY rnonucritoiv'or ALKALINE). EARTH .METAI cYANaMrnEs No Drawing. Application med July 1, matseria No. 548,266, and. in Germany uly 7, 1930.] J i The present invention relates to the production of alkaline earth metal cyanamides. I have found that by leading ammonia and aliphatic unsaturated hydrocarbons, es pecially those which are gaseous at ordinary. room temperature, asfor example acetylene, ethylene,'propylene and the'llke, over the;

oxides or-carbonates of the alkaline earth metals at temperaturesabove about .4009, but below 1000O., advantageously at red heat, the cyanamides of the alkaline, earth metals'a re obtained. The reaction proceeds,

for example when employing -1propylene and calcium oxide, according to the following The fact that this reaction can be carried out is surprising as there. are statements in the literature to the effect that calcium cyanamide is decomposed by hydrogen orthe nitrogenation in, the presence of hydrogen is injuriously affected to a great' 'extent.

The proportions of ammonia and hydrocarbons in the mixture may be. selected ac;

cording to desire; "they. depend, for example, upon which of thetvvo substances it is desired should be Converted to the largest cent by volume.

possible extent the concentration ofeach' of the said two reactants in the" gas mixture should, however, amount to at least 5 per The oxides and carbonates to be employed as initial materials or natural sources. T V p V The conversion of thereaction gases may be increased by' the" employment of 'cata lysts giving rise to the formation of hydro 'cyanic acid I from hydrocarbons and am monia, which are mixed with the oxides or carbonates or arranged in frontoffthem. Catalysts of the said nature are well-known in the art. As examples may be mentioned articular heavy metal oxides, such, ,as nic e1, chromium and copper oxides, and also aluminium oxide, especially when it is in the gel form.

It isadvantageous to arrangethe-catalyst so that the gas mixture first comes into contact with the catalyst and then with the a1 may be from industrial kalineearth metalcompound to be mirage nated. r

I have further found that particularly valuable catalysts foir'the purpose here in question are the phosphates of heavybase metals, preferably those'of the heavy metals of groups 5 to'j8' of the periodic'system'or of copper. As examples of such phosphates:

may be mentioned iron phosphate, copper phosphate and molybdenum phosphate. These phosphates are used "on supports.

tage that they are less'liable to become co'n- The said'catalysts have the great advang taminated with carbonblack or soot and These, are then kept for some timein a mg cupboard until'they have become hard,v when they are at once. ready for use. i The proportionof support jmaterial -for exam ple Chma clay to metal phosphate should preferably be such that the finished catalyst contains atfleast one per .gcent by weight of a heavy metal in "the form ofits phosphate,

but the amount of phosphate should not be so h1gl'1thatthe 'i'n'echanicallstrength of the. catalystsis'diminished. 1

so g5 The following examples will further il the invention is not restricted to these ex? amples. The-partsare by weight.

zont-al tube heated to about 600 Cgare treated in the course of l2 hourswith a gas current. consisting 1 ofiabout 13.9 parts of acetylene and 18.2wparts1or' l amn1onia."; 16

'lustrate" the nature of this invention,"but- I 20 parts of calcium carbonate parts of a product containing"30' .1v percent a of cyanamide nitrogen, i. re about 86 cent: of: calciumcyanamide areobtained.

32 per cent of the. acetylene is'converted j Jama- 217;

i parts-of i ammonia together partsof propylene are ledduring the course of 1 hours into the bottom of a vertical tube heated to 800 C. and filled with 90 parts of quicklime in a granulated form. 92' parts of a product containing 4.2 per cent ofi cyanamide nitrogen, i. e. about 12 per centof calcium cyanamide,l are obtained. About 6.8 per cent of the propylene is converted.

'{If the lime is'supported on a layer of aluminium oxide gel, under otherwise identical conditions 100 parts of a product con- 1 taining 22/1 .per cent'offnitrogen, i. e. about 64 per centof calcium cyanamide are obtained. In this case 40 per ce'nt'of the propylene converted.

. Ewample 3 1 EAbQUt BG parts of propylene and 120 parts of ammonia are led at 800 C. during the course. of 1 hours into the bottom of a vertical tube containing a layerof 150 parts ofgran ul arcalcium carbonate supported on a layer of aluminium oxide, 115 parts of a product containing 24.6 per cent or nitrogen i. e. about 70. per cent of calcium cyanamide are obtained. .Abfout, per centot the propylene converted. I f

' Example 4 90 parts of ammonia andp56 parts of propylene are led in the course of 1 hours into the bottom oi? a vertical tube heated. to 800. C. and containing 100 parts of barium oxide supported on a layer of aluminium oxide. 120 parts] of a product containing 7.2 per cent of cyanamide nitrogen, i. e. 45 per cent of barium cyanam1de are obtamed. 15 .4 per cent of the propylene s converted.

I Example 5 A-niixture of 50 partsof butylene with 1 05 parts of ammon a s passed in the course of. an hour at about 800 C. ln an upward; direction through. a vertlcally arranged tube,

"' in the lower part of which a layer of aluminium oxide gel'and above the latter .a layer of 50 partsof calcium oxide are arranged;

62 parts of a final product areobtained which contains.22.2 per cent of nitrogen, corresponding to 63.6 per cent of calcium cyanamide. The. butylene' is converted to the extent of 27.5 per cent.

Example 6 i 162 parts of ammonia and 62.5 parts of ethylene are passed at 800 C. in the course of an hour first over a catalyst containing 15 per cent of ferric phosphate which has been prepared'with the aid'of China, clay inthe manner described above, and then through partsof bu'rnt'lime containing 80 per cent of CaO. parts of a product are obtained which contains 23.7 per cent of cyanamide nitrogen, corresponding toa content of 67.7

5 Perce of al i m. an mide- 36 pe c nt of the ethylene used is converted in the said manner. 1

Ewample '7 210 parts of ammonia and 125 parts oi: ethylene are passed at 700 C. in the course of 2 hours first over the catalyst described in Example 6 and then through parts of burnt lime containing 80v per cent of CaO. 25 per cent of: the ethylene is'converted and parts of a product are obtained, which contains 25.8 percent oi: cyanamide nitrogen, corresponding. to 73.8 per cent of calcium cyanamide. m Y Y I I Example It underthe conditions described in Ex- 4 ample .7 a catalyst containing 15 per cent of copper phosphate in mixture withChina clay is used as the catalyst, at a temperature of 700 C. 120 parts of a product are obtained, which contains 15.4 per cent 0t cyanamide nitrogen, correspondingto 48.9 per cent of calcium cyanamide, 14.8 per cent ofthe ethylene used being converted.

If under otherwise same conditions molybdenum phosphate is'usedins'tead of copper phosphate at a temperature of 650 Q, a product is obtained which contains 178 per cent of cyanamide nitrogen corresponding.

to 50.9 per cent of calciumcyanamide, and 14.5 per cent of-the ethylene used is converted.

Example 9 l 180 parts of a'mmoniaand 123 parts of THE Example 10 ,180 parts of ammonia and 125 parts of ethylenelare passed at 700 C. in the course of 2 hours first over a catalyst consisting i J.-

of 25 parts copper phosphate, 25 parts of ferric phosphate and 50 parts of China clay and then over 120 parts of burnt lime containing 80 percent of .CaO Q The re action product, of which. 120 parts are ol tained, contains 17 per cent of cyanamide nitrogen corresponding to 49.9 per cent of calcium cyanamide. 16.7 ,per cent of the ethylene used are converted.

What; I claim is:

' j 1 The process of producing alkaline ,earth man cyanamides which comprises passing ammonia and an aliphatic, unsaturated hydrocarbon in-the gaseous state,

' each of said gases being present in an amount of at least 5 per cent' of the reaction gas; atatemperature between 400 and 1000 C. over a substance selected from the group c'onsistingofthe joxid'es'and carbonates of the alkaline earth metals.

2. The process of producing alkaline earth metalcyanamides which comprises passing ammonia and an aliphatic,- unsaturated hydrocarbon in the gaseous state, each of said gases being present in an amount of at least 5 per cent of the reaction gas, at a temperature between 600 and 800 C. over a substance selected from the group consisting of the oxides and carbonates of the alkaline earth metals.

8. The process of producing alkaline earth metal cyanamides which comprises passing ammonia and an aliphatic, unsaturated hydrocarbon which is gaseous at room temperature, each of said gases being present in an amount of at least 5 per cent of the reaction gas, at a temperature between 400 and 1000 C. over a substance selected from the group consisting of "the oxides and carbonates of the alkaline earth metals.

4. The process of producing alkaline earth metal cyanamides which comprises passing ammonia and ethylene, each of said gases being present in an amount of at least 5 per cent of the reaction gas at a tempera-- ture between 400 and 1000 C. over a substance selected from the group consisting of the oxides and carbonates of the alkaline earth metals. b

5. The process of producing alkaline earth metal cyanamides which comprises passing ammonia and propylene, each of said gases being present in an amount of at least 5 per cent of the reaction gas, at a temperature between 400 and 1000 C. over a substance selected from the group consisting of the oxides and carbonates of the alkaline earth metals.

6. The process of producing calcium cyanamide which comprises passing ammonia and aliphatic, unsaturated hydrocarbon in the gaseous state, each of said gases being present in an amount of at least 5 per cent of the reaction gas, at a temperature between 400 and 1000 C. over a substance selected from the group consisting of calcium oxide and calcium carbonate.

7. The process of producing alkaline earth metal cyanamides which comprises passing ammonia and analiphatic, unsaturated hydrocarbon in the gaseous state, each of said gases being present in an amount of at least, i 5 per cent of the reaction gas, at a temperature between 400 and 1000 C. over a catalyst giving rise to the formation of hydrocyanic acid from hydrocarbons and ammonia and then over asubstance selected from the group consisting of the oxides and carbonates of the alkaline earth metals.

- 8; The process of producing alkaline earth metal cyanamides which comprises passing ammonia'and an aliphatic, unsaturated hydrocarbonin the gaseous state, each of said gases being present in an amount of at-least 5 per cent of the reaction gas, at a tempera-- ture-between 400 and 1000 C. over a catalyst comprising a heavy base metal phos phate on a support and then over a substance selected from the group consisting of the oxides and carbonates of the alkaline earth metals.

9. The process of producing alkaline earth metal cyanamides which comprises passing ammonia and an aliphatic, unsaturated hydrocarbon in the gaseous state, each of said gases being present in an amount of at least 5 per cent of the reaction'gas, at a temperature between 400 and 1000 C. overa catalyst comprising copper phosphate on a support and then over a substance selected from the group consisting of the oxides and carbonates ofthe alkaline earth metals.

10. The process of producing alkaline earth metal cyanamides which comprises passing ammonia and an aliphatic unsaturated hydrocarbon in the gaseous state, each of said gases being present in an amount of at least 5 per cent of the reaction gas, at a temperature between 400 and 1000 C. over a catalyst comprising a phosphate of a heavy base metal of groups 5 to 8 of the periodic system on a support and then over a substance selected from the group consisting of a the oxides and carbonates of the alkaline earth metals.

11. The process of producing alkaline earth metal cyanamides which comprises passing ammonia and an aliphatic unsaturated hydrocarbon in thegaseous state, each of said gases being present in an amount of at least 5 per cent of the reactiongas, at a temperature between 400 and 1000 C. over a catalyst comprising ferric phosphate on a support and then over a substance selected from the group consisting of the oxides and carbonates of the, alkaline earth metals.

12. The process of producing alkaline earth metal cyanamides which comprises 7 passing ammonia and an aliphatic, unsaturated hydrocarbon in the gaseous state, each of said gases beingpresent in an amount of at least 5 per cent of the reaction gas, at a temperature between 400 and 1000 C. over lie gases being present in an amount of at least 5 per cent of the reaction gas, at a temperature between 600 and 800 C. over a catalyst comprising copper phosphate and ferric phosphate on China clay and then over a substance selected from the group consisting of the oxides and carbonates of the alkaline earth metals.

HANS ACKER. 

